As a science journalist who often covers politics, I feel obligated to disclose that I volunteered last weekend in Cleveland, Ohio for the campaign to elect Barack Obama.

This may make some readers uncomfortable. Until the first door opened it made me uncomfortable as well; not because I believed my ability to fairly cover science policy in the future would be compromised, nor even because I feared that the perceived conflict of interest would turn readers skeptical or editors wary, but because it ran counter to my fundamental identity as a journalist — someone who doesn't throw his lot in with a party or movement, much less a charismatic individual, but stands aside, loyal to the pursuit of truth. An advocate, not a partisan.

I was also discomfited by the rhetoric surrounding the volunteer experience, the descriptions of meaningfulness and fulfillment in tones verging on religious. Whether or not I am whole is, perhaps, a question yet to be concluded, but I do not turn to political participation to answer it.

But at the level where I feel certain of the difference between fact and opinion, I believed that Barack Obama needed to win this election in order for America to have a chance of reversing its decline.* So I went to Cleveland and wore an Obama button and knocked on doors and reminded people to vote. It felt good.

It was instructive, too: in large parts of the neighborhood to which I was assigned, perhaps one house in eight was boarded and abandoned, and most of the rest were slowly, obviously falling apart, residents no longer able to replace broken doors or shattered windows. More restaurants were shuttered than were open; only a few convenience stores were still in business. The area seemed to have once been handsome; the homes were well-built, lawns wide and streets tree-lined. This wasn't merely poverty. It was hopelessness embodied.

I have been in places far poorer, but the sheer, pervasive air of decline was something new. For all the economic collapse has affected me, constricting and making uncertain and provisional my hopes and dreams, its threat has been one of stasis rather than fall. But this neighborhood, which by all accounts is unexceptional in the once-great eastern industrial cities and in the towns between America's seaboards, seemed ready to vanish, to fall back into the earth. The fate of its residents would not be good.

They knew this. And they believed that Barack Obama would save them. I was unprepared for that, and I feared for their eventual disappointment, but the sincerity of their belief was humbling. It wasn't the sort of support to which I am accustomed — the outrage of well-educated liberals, grounded in principle rather than immediacy, able to contemplate a retreat to Canada if McCain won or a change in profession if the economy worsens. Not that such outrage, or such plans, are invalid; they are, after all, my own. But these people had nowhere to go, and they believed in what Barack Obama represented.

Whether their belief is well-placed can be debated, but its existence cannot. And its sheer, visceral realness is meaningful in itself. There is something incredible about inspiration, about hope . That Obama can provide it is significant, is a force for good, in a way I didn't previously comprehend. Hope started to grow in me, as well: not because Obama is perfect or wise, or his platform guaranteed of success, but because his presidency makes it possible to conceive, for a moment at least, of change.

Had John McCain won, or had Hillary Clinton defeated Obama in the Democratic primary and then taken the presidency, nobody would have danced in the streets. Dance we did, in cities across the country, in Brooklyn where I watched the results and poured into the streets with everyone else, hugging strangers and screaming and floating for a few hours on a feeling so uncommon now that I'd forgotten it: possibility.

Tuesday night was one of the most beautiful nights of my life, and I'll never forget it.

So what does this mean for me as a journalist, or for someone who sees an article of mine on the science policies of the Obama administration? In my defense I submit only that it's better to take a side openly than in secret; and that, in the end, I was motivated not by a desire to win but by a dream of what our society could and should be.** That dream now demands a return to my role as a journalist, loyal first and foremost to moral principle and the pursuit of truth. I'll cover Obama with the same rigor and skepticism as I did the Bush administration, if not more. His promises, and the people to whom he made them, deserve no less.

Note: In the interest of full disclosure, I voted in Maine, and selected a Republican, Susan Collins, as my Senator; and for offices in which I didn't know the nominees, wrote in myself or my friends.

* The consequences of climate change — agricultural and hydrological disruption, the resulting disease and dislocation and economic turmoil — are arguably the greatest challenges now facing the nation; overcoming them will require the transformation of our energy infrastructure and economy. That in turn will require a radical departure from what has been the political status quo; so will the management of a health care system that will soon devour as much federal money as the military.

Perhaps John McCain would have been able to lead the country on such a radical path, but I was not certain. Moreover, I was completely unconvinced that he could take the steps necessary to repair an economy wrecked by greed and the deregulation of corporate finance — a deregulation in which both Democrats and Republicans have been complicit, but McCain long cheered. And the willingness of McCain to put a wholly unqualified Sarah Palin in line to inherit the country's command purely for the sake of obtaining power erased any faith I had in his clarity of judgment.

** I'm aware that pure objectivity is, to some, a journalistic ideal. Non-partisanship is not, however, the same thing as objectivity. To quote Joan Didion's "Insider Baseball ":

When we talk about the process, then, we are talking, increasingly, not about "the democratic process," or the general mechanism affording the citizens of a state a voice in its affairs, but the reverse: a mechanism seen as so specialized that access to it is correctly limited to its own professionals, to those who manage policy and those who report on it, to those who run the polls and those who quote them, to those who ask and those who answer the questions on the Sunday shows, to the media consultants, to the columnists, to the issues advisers, to those who give the off-the-record breakfasts and to those who attend them; to that handful of insiders who invent, year in and year out, the narrative of public life. "I didn't realize you were a political junkie," Marty Kaplan, the former Washington Post reporter and Mondale speechwriter who is now married to Susan Estrich, the manager of the Dukakis campaign, said when I mentioned that I planned to write about the campaign; the assumption here, that the narrative should be not just written only by its own specialists but also legible only to its own specialists, is why, finally, an American presidential campaign raises questions that go so vertiginously to the heart of the structure.

I watched the first and third Presidential debates on CNN. After each one, the network cut to a panel of analysts, of whom many had previously worked for the Democrat or Republican party, who judged what we had just seen purely in terms of framing and performance. That sort of ostensibly evenhanded coverage, which subjectively favors a political process in which any statement of policy, belief or fact is rendered immediately superfluous, is a betrayal of democracy and the country; it is far more destructive than the worst and most cynical partisanship; and now that the election is over, I can only hope that CNN's political desk and producers move on to more socially valuable tasks, such as foreclosing on the elderly or denying medical comfort to the terminally ill.